1. Field of the Invention
This invention relates, in general, to cooking apparatus. More specifically, the invention relates to a control panel for a cooking apparatus through which a user may input desired cooking conditions, such as, e.g., cooking time or a desired cooking mode.
2. Description of the Prior Art
Well known cooking apparatus, such as microwave ovens, typically are provided with a control panel. A plurality of cooking condition keys, such as, e.g., a start key, a cancel key, a plurality of cooking mode keys, etc. normally are arranged on the control panel.
An example of the above-described control panel is disclosed in U.S. Pat. No. 4,145,584 issued on Mar. 20, 1979 in the name of Jon L. Otterlei, and entitled FLEXIBLE KEYBOARD SWITCH WITH INTEGRAL SPACER PROTRUSIONS. In this prior art, a plurality of cooking condition set keys including a plurality of cooking mode keys, a cancel key, a start key etc., are provided on one side of a fold line of a Mylar sheet. A plurality of conductive areas corresponding to the cooking condition set keys are arranged on the corresponding rear surface of the Mylar sheet. A key-matrix circuitry comprises those conductive areas connected to one another. A plurality of key scanning signal lines connected between the key-matrix circuitry and a main control section are formed on the rear surface of the Mylar sheet. A plurality of conductive elements corresponding to the conductive areas are provided on the rear surface of the Mylar sheet at the opposite side of the fold line from the set keys. Each conductive element includes a pair of terminals. A key signal line formed on the opposite side of the rear surface is connected to each conductive element. When the sheet is folded along the fold line, each conductive area of one side surface and the corresponding conductive element come into appositon, to act as a fixed contact of a normally open single-pole single-throw switch. For example, when a desired key is pressed, the corresponding conductive area comes into contact with the opposite conductive element. Therefore, the conductive area makes the pair of terminals of the conductive element electrically contact with one another therethrough.
In this arrangement described above, since a large number of signal lines are provided on one sheet, the arrangement of those signal lines is complicated, and a large sheet is needed for arranging those signal lines and the cooking condition set keys.